Ch 35 pt 1 Flashcards
Neurons
“nerve cells”
Specialized cels that transmit nerve impulses
(Sensory vs Motor)
Sensory Neurons
“afferent neurons” - bring something to it
Part of central nervous system
Motor Neurons
“efferent neurons” - takes something away from it
Part of central nervous system
Interneurons
Transmits signals between other neurons
Unipolar Neuron
One structure coming away from soma
(in insects only)
Bipolar Neuron
One dendrite and one axon coming off the central cell
Multipolar Neuron
Most common in Central nervous system
Branching dendrites from central cell
Pseudopolar Neuron
One process branch away from central cell, but that process branched into two ways
Dendrites
Receives information
Cell Body
Produces neurotransmitters
Axon
Transmits information
Synaptic terminal
Release neurotransmitters
Myelin Sheath
Insulate transmission
(Helps speeds up transmitting process)
Nodes of Ranvier
Impulse conduction
(Helps speed up the transmitting process)
Photoreceptors
Vision
Mechanoreceptors
Tactile (touch)
Auditory (hearing)
Chemoreceptors
Olfactory (smell)
Gustatory (taste)
Thermoreceptors
Temperature, mostly found in hypothalamus
Baroreceptors
Blood pressure
Schwann Cells
In Peripheral nervous system
Housed between cell and axon
Myelinate one neurons
Oligodendrocytes
In Central nervous system
Myelinate multiple neurons
Astrocytes
In Central nervous system
Structural support of synapse and forms a blood brain barrier
Microglia (CNS) / Peripheral macrophages (PNS)
Recycle and repair damaged cells
“immune system” of nerves system
Satellite glia
Peripheral nervous system
Nutrients and structure
Radial glia
Central Nervous system
Scaffolding and guides developing neurons
Ependymal
Central Nervous system
Line fluid-filled cavities and Cerebralspinal fluid homeostasis
[Clearance of waste]
Resting Potential
Electrochemical gradients (High->low)
-70 mV (Linked with K+ permeability)
Depolarize membrane
Make it less negative
Polarize membrane
Make it more negative (But not below resting potential)
Hyperpolarize membrane
Make more negative than resting potential
Small stimulus
Na+ leaks in causing a slight depolarization (doesn’t open ion channels)
Strong stimulus
Na+ leaks in and the threshold is reached (opens the ion channels)
Self propagation
Unmyelinated axon
Influx of Na+ caused a depolarization of adjacent area
Causes a “wave” effect through axon
Saltatory Conduction
Adds insulation (helps signal travel faster, because it skips over Schwann cells)
Synaptic cleft
Intercellular junctions between neurons and (other neurons, muscle cells, or gland cells)
Paracrine signaling between axon and dendrites on another neuron through this
Presynaptic cell (axon to synapse)
Postsynaptic cell (synapse to cell)
Chemical Synapse
No direct connection to the synaptic cleft
20-40 nm wide (very small)
Synaptic vesicles hold neurotransmitters
Neurotransmitters
A substance that transmits nerve impulses across synapse
Is a chemical reaction stored in the synaptic vesicles
Acetylcholine (ACh)
Type of Neurotransmitter
Neuromuscular junction
Excitatory Postsynaptic Potential
May lead to depolarization of membrane
y-aminobutyric acid (GABA)
Important inhibitor of brain function
Inhibitory Postsynaptic Potential
Causes hyperpolarization
Nervous System
Central vs Peripheral
Peripheral - Sensory and Motor
Motor - Somatic (voluntary) and Autonomic (involuntary)
